<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <style>
        body
        {
            background-color: mediumturquoise;
        }
        .child {
            width: 300px;
            height: 100px;
            padding: 20px;

            position: absolute;
            top: 50%;
            left: 50%;

            margin: -70px 0 0 -170px;
        }
    </style>
</head>
<body>
<div>
    <h1 class="child">Hello Golang</h1>
</div>
</body>
</html>
